Single-stranded DNA Binding (SSB) protein is essential for replication of the chromosome of E. coli. In addition, SSB participates in the recombination and repair of E. coli DNA. The SSB protein is thought to function primarily by binding to single-stranded DNA that is formed transiently during these processes. We have crystallized both the full length and truncated SSB in a complex with single-stranded DNA. Crystals of the full-length protein / DNA complex are hexagonal and diffract to 4 w resolution. It would be advantageous to use synchrotron radiation to get higher resolution data from such a big cell.